Wildfires continue to burn in parts of the UK as firefighters face “extreme pressure” due to the prolonged heatwave, the chair of the National Fire Chiefs Council (NFCC) has warned.

Phil Garrigan told BBC Breakfast that the dry weather increased the risk of uncontrollable fires and said: “There’s no real respite… There doesn’t seem to be any rain forecast and that becomes problematic”.

Around 19 fires remain active across the country, he added.

Major incidents were declared in Conwy, north Wales, and in Glossop, Derbyshire, on Sunday, with firefighters still tackling the flames on Tuesday.

Wildfires over the weekend also affected Hampshire, Durham, West Sussex, East Sussex, Devon and Somerset.

In Wales, the major incident declared over the Conwy wildfire has now been brought under control, according to North Wales Fire and Rescue Service assistant chief fire officer Justin Evans.

But firefighters are still tackling several active blazes, including in Braichmelyn forestry near Bethesda and the Rhinogydd mountain range near Harlech.

Farmer Gareth Wyn Jones, whose land borders the Conwy Mountain, said he had “never seen anything of that scale”.

“It was unreal,” he said, adding that while ponies grazing on the mountain had escaped, he feared for a neighbour’s pigs as flames swept through surrounding land.

“The biggest worry was that they were going to suffocate in the smoke, but the smoke did carry over them,” he said, confirming the animals had survived.

Elsewhere, firefighters remain at the scene of a major moorland fire at Tintwistle Moor near Dovestone Reservoir in the Peak District.

Around 30 to 40 firefighters are continuing to tackle the blaze, which began on 24 June and has burned around 260 hectares (642 acres) of moorland and woodland.

Greater Manchester Fire and Rescue Service senior fire chief Ben Levy warned crews faced “a very challenging and gruelling day ahead” as high temperatures, strong winds and dry conditions continued to fuel the fire.

He urged people to take extra care in the countryside to reduce the risk of further wildfires.

Shania Care-Slede, 20, from Hyde, was arrested earlier this week on suspicion of arson related to the Dovestone fire.

She was charged with aggravated arson, reckless endangerment of life and dangerous driving, Greater Manchester Police said on Tuesday.

In Dorset, firefighters spent the night at the scene of a wildfire on heathland.

Smoke was reported at Agglestone, near Studland, at about 17:00 BST on Monday, with crews from seven stations tackling the blaze until 20:00. Relief teams are expected to remain throughout Tuesday.

Natural England, is warning of a “very high” or “exceptional” risk of fires across much of England – as well as Wales – over the next few days.

Dry weather does not, on its own, cause wildfires – there needs to be a source of ignition too, such as a spark from a barbecue or a discarded cigarette.

However, dry conditions remove moisture from vegetation, making it more able to burn and act as fuel for blazes to take hold and spread.

The conditions the UK is experiencing so far this summer mirror the warnings given by climate scientists that human-induced climate change would lead to more frequent and intense heatwaves, as well as potential summer droughts.

Additional reporting: Angharad Thomas